반응 #56720

반응 방정식

THF

ethyl cyanoacetate

1-methylcyclopropane-methanol

PCC

→

ester

수율 26.2%

2-Cyano-3-(1-methyl-cyclopropyl)-acrylic acid ethyl ester

수율 26.2%

용매

CH2Cl2

반응 조건

후처리

1. 1
   여과The mixture was filtered through a 1 cm plug of silica gel under vacuum
2. 2
   세척rinsed with Et2O
3. 3
   농축The filtrate was concentrated to ca. 5 mL total volume
4. 4
   기타partitioned between Et2O and sat. aq. NaHCO3
5. 5
   기타The phases were separated
6. 6
   세척the organic phase washed with brine
7. 7
   건조dried (MgSO4)
8. 8
   농축concentrated

실험 절차

To 1-methylcyclopropane-methanol (Aldrich, 1.13 mL, 11.6 mmol) in 50 mL CH2Cl2 was added neutral alumina (2.5 g) and then PCC (2.5 g, 11.6 mmol), and the mixture stirred 3 h at ambient temperature. The mixture was filtered through a 1 cm plug of silica gel under vacuum, and rinsed with Et2O. The filtrate was concentrated to ca. 5 mL total volume. To the residue was added THF (10 mL), ethyl cyanoacetate (1.2 mL, 11.3 mmol), piperidine (5 drops), and finally acetic acid (5 drops). The whole was stirred at ambient temperature overnight, then partitioned between Et2O and sat. aq. NaHCO3. The phases were separated and the organic phase washed with brine, dried (MgSO4), and concentrated. Flash chromatography of the residue (10→15% EtOAc/hexanes) provided 0.53 g (25%) of the ester as a colorless oil that crystallized on standing. Anal. Calcd for C10H13NO2: C, 67.02; H, 7.31; N, 7.82. Found: C, 66.86; H, 7.47; N, 7.70.

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